Elly is a member of the Ecosystem and Landscape Dynamics (ELD) group within the Institute for Biodiversity and Ecosystem Dynamics (IBED). Elly is a soil ecologist interested in the interaction between plant communities and soil communities including micro- and macro-fauna. Her strength lies in analyzing and understanding interactions in multi-community data to unravel transition effects in natural systems. She is primarily a fundamental scientist interested in the mechanisms that drive these transitions in plant- and soil communities. However, she is also involved in teaching in the bachelor FPS and the master Earth sciences, within the track Environmental management and the track Future Planet Ecosystem Sciences.
I am a soil ecologist interested in the interaction between plant communities and soil communities including micro- and macro-fauna. My strength lies in analyzing and understanding interactions in multi-community data to unravel transition effects in natural systems. I am primarily a fundamental scientist interested in the mechanisms that drive these transitions in plant- and soil communities. However, I am also investigating the possibilities of soil community manipulations to speed up nature restoration processes and to find tools that might help nature conservation organizations to quick and safe restore previously degraded lands. I am specifically interested in how food web interactions drive the soil community composition in the root-zone. Until now I have looked at carbon flows through the soil food web with the use of stable isotopes on the effects of soil community change in a successional gradient. I could relate these functional data to a large scale field sampling campaign in the same successional gradient, which made it possible to correlate field abundances and biomass to carbon turnover in a wide range of soil biota (bacteria, fungi, nematodes, mites, collembola, enchytraeids, earthworms and spiders. Currently, I investigate the influence of plant root exudates on soil community assemblages with a special interest for mutualistic and potential plant pathogenic fungi. In the near future I would also like to look at the change in quality of plant litter during secondary succession and how this influences soil organic matter formation which will also affect the soil community assemblage in the root zone. In this way direct and indirect plant effects are reflected in the soil community assemblage and then feed-back to the next generation of plants. Understanding these mechanism will open a myriad of possibilities of better understanding and potential influencing ecosystem transitions.
Next to research I teach:
1. In the bachelor FPS (major aardwetenschappen) in the courses Soils & environment, Soil & crop quality lab (course coordinator since 2017) and Desertification and Land Degradation. Besides the coaching of bachelor students during their bachelor project, see under "Student projects".
2. In the master Earth sciences I teach in the course Biogeochemical cycles (track Enivronmental Sciences) and Grand Challenges of human-ecosystem interactions (track Future Planet Ecosystem Sciences). Besides, I have guide some students during their masters project, see under "Student projects".
2011- Wageningen University/Netherlands Institute of Ecology - Terrestrial Ecology
Title of thesis: Climate induced range-expanding plants: above- and belowground interactions
2005- Vrije Universiteit Amsterdam – Ecology
2003- Vrije Universiteit Amsterdam – Biology
2015- VENI-NWO grant.
2009- Best student presentation, British Ecological Society (BES) Specialist Interest Group ‘Invasive Species’.
2009- Best paper prize for the Engelkes et al. 2008 paper, Netherlands and Flemish Ecological Society (Necov) Annual meeting.
Karen Muñoz-Cárdenas. Title of thesis: “What lies beneath? Linking litter and canopy food webs to protect ornamental crops” University of Amsterdam, Date of defence: June 21, 2017.
Minggang Wang. Title of thesis: “Arriving at the right time: A temporal perspective on above-belowground herbivore interactions” Wageningen University, Date of defence: June 08, 2016.
2016 - Education Board for the Bachelor Future Planet Studies at University of Amsterdam.
2017 - Associate editor of Funtional Ecology
The majority of current theory on plant community ecology has been based on vegetation succession at abandoned arable land. This shows how habitat filtering and competition for limiting resources structures plant community composition. Currently, there is consensus that plant community development is the result of those factors, as well as of interactions with their soil community. Here, we address the question how soil community structure affect nitrogen and carbon cycling during secondary succession. In 2011, we visited 9 grassland sites, categorized as recent, mid-term, long-term abandoned ex-arable fields. Bacteria and fungi were identified by pyrosequencing, while archaea were identified using TRFLP. The protists, micro-fauna, nematodes, enchytraeids and earthworms were extracted and morphologically identified until high taxonomic levels, often species level. In total, around 15 000 species were identified from the soils. We created a Spearman-rank correlation matrix based on abundance data of species which we visualized in a network as an overview of the soil community present. In 2012, intact soil cores with comparable plant vegetation were collected from the same sampling points. Stable isotope probing of the cores was performed using dual labelled 15N ammonium nitrate (15NH415NO3) and 13C was fed to the plants in the form of 13CO2. The soil food web structure was resolved by identifying the microbes using phospholipid markers and identifying soil fauna by morphology into similar groups as for the network analysis, both combined with isotopic measurements.
We provide evidence that the conversion of soil food web structure appears to be more important than a quantitative change in biodiversity as such. Moreover, we show that structural changes in the food web topology also leads to functional changes in the soil food web which can act as a driving force during land use change after human disturbance. Stable isotope analysis showed that plants in the long-term abandoned soil cores allocated less newly photosynthesized carbon to their roots and took up less nitrogen from the soil. Stable isotope analysis also showed that fungi and their consumers become more important in later successional stages, but that the fungal to bacterial ratio stayed constant over time. We can conclude that during secondary succession the system shifts in terms of function from bacterial dominated to fungal dominated. However, most changes in correlation strength of the network already occur in the early stages of secondary succession, suggesting that succession effects continue on a functional level after most interaction pathways become established in early successional stages.
Next step is to find out not only what kind of community profile changes occur during secondary succession, but also whether we can manipulate the process by introducing later successional soil with microbes and fauna into early successional soil.
Master project I: Enzymatic activities of microbial communities in a land abandonment chronosequence
From an earlier experiment I have soil DNA extracts. In this experiment the soil biodiversity of the microbes was manipulated. I already have a full sequencing profile of the fungal and bacterial community, but I would like to the active functional genes expressed in the fungal community to look at biodiversity -function relationships in a secondary succession context where ex-arable lands are converted into natural grasslands. I am interested in the functional changes in the soil biota related to this land-use transition. Therefore, I would like to test these soils in an hydrolitic enzyme essays where enzymatic activity is tested fo enzymes involved in the C, N and P cycle
Required: Basic lab experience.
Methods used: hydrolitic enzym essay
Starting time: any time is possible but January 2018 is preferred.
Master project II: Speed-up of secondary succession by soil and microbe/fauna transplantation
I look for students that are interested in measuring microbes or fauna, such as nematodes, mites, collembola, spiders or earthwoms, (or even have experience in fauna determination) in an experiment where I want to label living soil cores with stable C and N isotopes. Transplanting of successional stages will be done, whereafter the function of the soil micro- and meso-fauna will be monitored using molecular sequencing techniques for community profiling and community response profile and hydrolitic enzyme activity for function.
Required: Affinity with soil biota, microbiology or soil animals.
Methods used: Oostenbrink elutrator, Tullgren, CRP, hydrolytic enzym essays
Starting time: Preferably from out May 2018.